1 #ifndef _LINUX_KPROBES_H
2 #define _LINUX_KPROBES_H
4 * Kernel Probes (KProbes)
5 * include/linux/kprobes.h
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License as published by
9 * the Free Software Foundation; either version 2 of the License, or
10 * (at your option) any later version.
12 * This program is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 * GNU General Public License for more details.
17 * You should have received a copy of the GNU General Public License
18 * along with this program; if not, write to the Free Software
19 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
21 * Copyright (C) IBM Corporation, 2002, 2004
23 * 2002-Oct Created by Vamsi Krishna S <vamsi_krishna@in.ibm.com> Kernel
24 * Probes initial implementation ( includes suggestions from
26 * 2004-July Suparna Bhattacharya <suparna@in.ibm.com> added jumper probes
27 * interface to access function arguments.
28 * 2005-May Hien Nguyen <hien@us.ibm.com> and Jim Keniston
29 * <jkenisto@us.ibm.com> and Prasanna S Panchamukhi
30 * <prasanna@in.ibm.com> added function-return probes.
32 #include <linux/compiler.h> /* for __kprobes */
33 #include <linux/linkage.h>
34 #include <linux/list.h>
35 #include <linux/notifier.h>
36 #include <linux/smp.h>
37 #include <linux/bug.h>
38 #include <linux/percpu.h>
39 #include <linux/spinlock.h>
40 #include <linux/rcupdate.h>
41 #include <linux/mutex.h>
42 #include <linux/ftrace.h>
45 #include <asm/kprobes.h>
47 /* kprobe_status settings */
48 #define KPROBE_HIT_ACTIVE 0x00000001
49 #define KPROBE_HIT_SS 0x00000002
50 #define KPROBE_REENTER 0x00000004
51 #define KPROBE_HIT_SSDONE 0x00000008
53 #else /* CONFIG_KPROBES */
54 typedef int kprobe_opcode_t;
55 struct arch_specific_insn {
58 #endif /* CONFIG_KPROBES */
63 struct kretprobe_instance;
64 typedef int (*kprobe_pre_handler_t) (struct kprobe *, struct pt_regs *);
65 typedef int (*kprobe_break_handler_t) (struct kprobe *, struct pt_regs *);
66 typedef void (*kprobe_post_handler_t) (struct kprobe *, struct pt_regs *,
68 typedef int (*kprobe_fault_handler_t) (struct kprobe *, struct pt_regs *,
70 typedef int (*kretprobe_handler_t) (struct kretprobe_instance *,
74 struct hlist_node hlist;
76 /* list of kprobes for multi-handler support */
77 struct list_head list;
79 /*count the number of times this probe was temporarily disarmed */
80 unsigned long nmissed;
82 /* location of the probe point */
83 kprobe_opcode_t *addr;
85 /* Allow user to indicate symbol name of the probe point */
86 const char *symbol_name;
88 /* Offset into the symbol */
91 /* Called before addr is executed. */
92 kprobe_pre_handler_t pre_handler;
94 /* Called after addr is executed, unless... */
95 kprobe_post_handler_t post_handler;
98 * ... called if executing addr causes a fault (eg. page fault).
99 * Return 1 if it handled fault, otherwise kernel will see it.
101 kprobe_fault_handler_t fault_handler;
104 * ... called if breakpoint trap occurs in probe handler.
105 * Return 1 if it handled break, otherwise kernel will see it.
107 kprobe_break_handler_t break_handler;
109 /* Saved opcode (which has been replaced with breakpoint) */
110 kprobe_opcode_t opcode;
112 /* copy of the original instruction */
113 struct arch_specific_insn ainsn;
116 * Indicates various status flags.
117 * Protected by kprobe_mutex after this kprobe is registered.
122 /* Kprobe status flags */
123 #define KPROBE_FLAG_GONE 1 /* breakpoint has already gone */
124 #define KPROBE_FLAG_DISABLED 2 /* probe is temporarily disabled */
125 #define KPROBE_FLAG_OPTIMIZED 4 /*
126 * probe is really optimized.
128 * this flag is only for optimized_kprobe.
130 #define KPROBE_FLAG_FTRACE 8 /* probe is using ftrace */
132 /* Has this kprobe gone ? */
133 static inline int kprobe_gone(struct kprobe *p)
135 return p->flags & KPROBE_FLAG_GONE;
138 /* Is this kprobe disabled ? */
139 static inline int kprobe_disabled(struct kprobe *p)
141 return p->flags & (KPROBE_FLAG_DISABLED | KPROBE_FLAG_GONE);
144 /* Is this kprobe really running optimized path ? */
145 static inline int kprobe_optimized(struct kprobe *p)
147 return p->flags & KPROBE_FLAG_OPTIMIZED;
150 /* Is this kprobe uses ftrace ? */
151 static inline int kprobe_ftrace(struct kprobe *p)
153 return p->flags & KPROBE_FLAG_FTRACE;
157 * Special probe type that uses setjmp-longjmp type tricks to resume
158 * execution at a specified entry with a matching prototype corresponding
159 * to the probed function - a trick to enable arguments to become
160 * accessible seamlessly by probe handling logic.
162 * Because of the way compilers allocate stack space for local variables
163 * etc upfront, regardless of sub-scopes within a function, this mirroring
164 * principle currently works only for probes placed on function entry points.
168 void *entry; /* probe handling code to jump to */
171 /* For backward compatibility with old code using JPROBE_ENTRY() */
172 #define JPROBE_ENTRY(handler) (handler)
175 * Function-return probe -
177 * User needs to provide a handler function, and initialize maxactive.
178 * maxactive - The maximum number of instances of the probed function that
179 * can be active concurrently.
180 * nmissed - tracks the number of times the probed function's return was
181 * ignored, due to maxactive being too low.
186 kretprobe_handler_t handler;
187 kretprobe_handler_t entry_handler;
191 struct hlist_head free_instances;
195 struct kretprobe_instance {
196 struct hlist_node hlist;
197 struct kretprobe *rp;
198 kprobe_opcode_t *ret_addr;
199 struct task_struct *task;
203 struct kretprobe_blackpoint {
208 struct kprobe_blackpoint {
210 unsigned long start_addr;
214 #ifdef CONFIG_KPROBES
215 DECLARE_PER_CPU(struct kprobe *, current_kprobe);
216 DECLARE_PER_CPU(struct kprobe_ctlblk, kprobe_ctlblk);
219 * For #ifdef avoidance:
221 static inline int kprobes_built_in(void)
226 #ifdef CONFIG_KRETPROBES
227 extern void arch_prepare_kretprobe(struct kretprobe_instance *ri,
228 struct pt_regs *regs);
229 extern int arch_trampoline_kprobe(struct kprobe *p);
230 #else /* CONFIG_KRETPROBES */
231 static inline void arch_prepare_kretprobe(struct kretprobe *rp,
232 struct pt_regs *regs)
235 static inline int arch_trampoline_kprobe(struct kprobe *p)
239 #endif /* CONFIG_KRETPROBES */
241 extern struct kretprobe_blackpoint kretprobe_blacklist[];
243 static inline void kretprobe_assert(struct kretprobe_instance *ri,
244 unsigned long orig_ret_address, unsigned long trampoline_address)
246 if (!orig_ret_address || (orig_ret_address == trampoline_address)) {
247 printk("kretprobe BUG!: Processing kretprobe %p @ %p\n",
248 ri->rp, ri->rp->kp.addr);
253 #ifdef CONFIG_KPROBES_SANITY_TEST
254 extern int init_test_probes(void);
256 static inline int init_test_probes(void)
260 #endif /* CONFIG_KPROBES_SANITY_TEST */
262 extern int arch_prepare_kprobe(struct kprobe *p);
263 extern void arch_arm_kprobe(struct kprobe *p);
264 extern void arch_disarm_kprobe(struct kprobe *p);
265 extern int arch_init_kprobes(void);
266 extern void show_registers(struct pt_regs *regs);
267 extern kprobe_opcode_t *get_insn_slot(void);
268 extern void free_insn_slot(kprobe_opcode_t *slot, int dirty);
269 extern void kprobes_inc_nmissed_count(struct kprobe *p);
271 #ifdef CONFIG_OPTPROBES
273 * Internal structure for direct jump optimized probe
275 struct optimized_kprobe {
277 struct list_head list; /* list for optimizing queue */
278 struct arch_optimized_insn optinsn;
281 /* Architecture dependent functions for direct jump optimization */
282 extern int arch_prepared_optinsn(struct arch_optimized_insn *optinsn);
283 extern int arch_check_optimized_kprobe(struct optimized_kprobe *op);
284 extern int arch_prepare_optimized_kprobe(struct optimized_kprobe *op);
285 extern void arch_remove_optimized_kprobe(struct optimized_kprobe *op);
286 extern void arch_optimize_kprobes(struct list_head *oplist);
287 extern void arch_unoptimize_kprobes(struct list_head *oplist,
288 struct list_head *done_list);
289 extern void arch_unoptimize_kprobe(struct optimized_kprobe *op);
290 extern kprobe_opcode_t *get_optinsn_slot(void);
291 extern void free_optinsn_slot(kprobe_opcode_t *slot, int dirty);
292 extern int arch_within_optimized_kprobe(struct optimized_kprobe *op,
295 extern void opt_pre_handler(struct kprobe *p, struct pt_regs *regs);
298 extern int sysctl_kprobes_optimization;
299 extern int proc_kprobes_optimization_handler(struct ctl_table *table,
300 int write, void __user *buffer,
301 size_t *length, loff_t *ppos);
304 #endif /* CONFIG_OPTPROBES */
305 #ifdef CONFIG_KPROBES_ON_FTRACE
306 extern void kprobe_ftrace_handler(unsigned long ip, unsigned long parent_ip,
307 struct ftrace_ops *ops, struct pt_regs *regs);
308 extern int arch_prepare_kprobe_ftrace(struct kprobe *p);
312 /* Get the kprobe at this addr (if any) - called with preemption disabled */
313 struct kprobe *get_kprobe(void *addr);
314 void kretprobe_hash_lock(struct task_struct *tsk,
315 struct hlist_head **head, unsigned long *flags);
316 void kretprobe_hash_unlock(struct task_struct *tsk, unsigned long *flags);
317 struct hlist_head * kretprobe_inst_table_head(struct task_struct *tsk);
319 /* kprobe_running() will just return the current_kprobe on this CPU */
320 static inline struct kprobe *kprobe_running(void)
322 return (__this_cpu_read(current_kprobe));
325 static inline void reset_current_kprobe(void)
327 __this_cpu_write(current_kprobe, NULL);
330 static inline struct kprobe_ctlblk *get_kprobe_ctlblk(void)
332 return (&__get_cpu_var(kprobe_ctlblk));
335 int register_kprobe(struct kprobe *p);
336 void unregister_kprobe(struct kprobe *p);
337 int register_kprobes(struct kprobe **kps, int num);
338 void unregister_kprobes(struct kprobe **kps, int num);
339 int setjmp_pre_handler(struct kprobe *, struct pt_regs *);
340 int longjmp_break_handler(struct kprobe *, struct pt_regs *);
341 int register_jprobe(struct jprobe *p);
342 void unregister_jprobe(struct jprobe *p);
343 int register_jprobes(struct jprobe **jps, int num);
344 void unregister_jprobes(struct jprobe **jps, int num);
345 void jprobe_return(void);
346 unsigned long arch_deref_entry_point(void *);
348 int register_kretprobe(struct kretprobe *rp);
349 void unregister_kretprobe(struct kretprobe *rp);
350 int register_kretprobes(struct kretprobe **rps, int num);
351 void unregister_kretprobes(struct kretprobe **rps, int num);
353 void kprobe_flush_task(struct task_struct *tk);
354 void recycle_rp_inst(struct kretprobe_instance *ri, struct hlist_head *head);
356 int disable_kprobe(struct kprobe *kp);
357 int enable_kprobe(struct kprobe *kp);
359 void dump_kprobe(struct kprobe *kp);
361 #else /* !CONFIG_KPROBES: */
363 static inline int kprobes_built_in(void)
367 static inline int kprobe_fault_handler(struct pt_regs *regs, int trapnr)
371 static inline struct kprobe *get_kprobe(void *addr)
375 static inline struct kprobe *kprobe_running(void)
379 static inline int register_kprobe(struct kprobe *p)
383 static inline int register_kprobes(struct kprobe **kps, int num)
387 static inline void unregister_kprobe(struct kprobe *p)
390 static inline void unregister_kprobes(struct kprobe **kps, int num)
393 static inline int register_jprobe(struct jprobe *p)
397 static inline int register_jprobes(struct jprobe **jps, int num)
401 static inline void unregister_jprobe(struct jprobe *p)
404 static inline void unregister_jprobes(struct jprobe **jps, int num)
407 static inline void jprobe_return(void)
410 static inline int register_kretprobe(struct kretprobe *rp)
414 static inline int register_kretprobes(struct kretprobe **rps, int num)
418 static inline void unregister_kretprobe(struct kretprobe *rp)
421 static inline void unregister_kretprobes(struct kretprobe **rps, int num)
424 static inline void kprobe_flush_task(struct task_struct *tk)
427 static inline int disable_kprobe(struct kprobe *kp)
431 static inline int enable_kprobe(struct kprobe *kp)
435 #endif /* CONFIG_KPROBES */
436 static inline int disable_kretprobe(struct kretprobe *rp)
438 return disable_kprobe(&rp->kp);
440 static inline int enable_kretprobe(struct kretprobe *rp)
442 return enable_kprobe(&rp->kp);
444 static inline int disable_jprobe(struct jprobe *jp)
446 return disable_kprobe(&jp->kp);
448 static inline int enable_jprobe(struct jprobe *jp)
450 return enable_kprobe(&jp->kp);
453 #endif /* _LINUX_KPROBES_H */